Bismuth vanadate occurs in nature in an orthorhombic form commonly called pucherite. Pucherite is a dull yellow-brown mineral, which is not useful as a pigment. Pucherite is similar in color to limonite, a dull yellow-brown iron oxide, which has never been produced as a bright, high intensity pigment despite repeated attempts.
Various references have described the synthetic preparation of bismuth vanadate, for example, I. M. Gottlieb and C. R. Rowe, "Preparation and Thermal Properties of Bismuth Orthovanadate", Thermal Analysis, Vol. 2, Proceedings Third ICTA DAVOS (1971), pp. 303-311; R. S. Roth and J. W. Waring, "Synthesis and Stability of Bismutotantalite, Stibiotantalite and Chemically Similar ABO.sub.4 Compounds", The American Mineralogist, Vol. 48 (Nov. - Dec., 1963), pp. 1348-56; H. E. Swanson et al., "Standard X-Ray Diffraction Powder Patterns", National Bureau of Standards Report, No. 7592 (Aug., 1962); Eduard Zintl and Ludwig Vanino, "Process For The Manufacture Of Pure Bismuth Vanadate"; German Pat. No. 422,947 (1925). However, as in the case of yellow iron oxide, none of the above references provide a process which is successful for use in the preparation of bismuth vanadate which is useful as a bright yellow pigment.